Cathode mount making apparatus



Aug. 21, 1951 J. FLAWS, JR 2,565,126

' CATHODE MOUNT MAKING APPARATUS Filed Jan. 22, 1947 2 Sheets-Sheet l 5&4. F1955.

Aug. 21, 1951 J. FLAWS, JR

CATHODE MOUNT MAKING APPARATUS 2 Sheets-Sheet Filed Jan. 22, 1947 m wwwm T efl 42% Figs Patented Aug. 21, 1951 CATHODE MOUNT MAKING APPARATUS John Flaws, Jr., East Cleveland, Ohio, assignor to General Electric Company, a corporation of New York Application January 22, 1947, Serial No. 723,528

7 Claims.

an electrode assembly or mount comprised of the electrode or cathode and the adjacent end portion of the envelope of the high voltage or so-called cold cathode type of discharge lamp or tube. More particularly, my invention relates to apparatus for fusing one end of a relatively short vitreous envelope tube and a vitreous exhaust tube about the metal supporting and leading-in wires extending from a cathode to form an assembly constituting one end of a discharge lamp. In succeeding operations in the manufacture of the discharge lamp, not a part of the present invention, the lamp is completed by sealingv such assemblies to opposite ends of a long tubular envelope and then exhausting and gas filling the lamp through the exhaust tubes of the assemblies.

One object of my invention is to provide appa ratus for sealing an end of a relatively short portion of the lamp envelope about metal supportin members of the lamp cathode to shape and seal the end of the envelope and mount the cathode at the desired relation therein. The manufacture of the end portions of a discharge lamp as a separate unit in apparatus of my invention imparts the advantages of low cost and very uniform manufacture to a critical portion of such lamps. Further advantages are realized by the use of such end portions in the manufacture of the complete lamp since said portions can then be made of standardized designs and their manufacture divorced from that of the main portion of the envelope which usually takes the form of letters or a design of some particular configuration and which is made specially to meet some particular need or requirement. Another object of my invention is to provide automatically operating apparatus for fusing and sealing one end of a relatively short portion of the envelope of a discharge lamp and a vitreous exhaust tube about 1eading-in and support wires extending from a cathode while maintaining said cathode at a specific relation thereto and maintaining the passage through said exhaust tube. The apparatus provides a means of making uniformly strong and satisfactory discharge lamp end portions in a manner generally more controllable and satisfactory than heretofore.

Other objects and advantages of my invention will appear from the following detailed description of a species thereof and from the accompanying drawing.

In the drawing Fig. 1 is a fragmentary plan view of a species of apparatus comprising my invention; Fig. 2 is a side elevation of a head of the apparatus and means associated therewith at-station B of Fig. 1; Fig. 3 is a plan view of a head of the apparatus; Figs. 4- and 5 are side elevations of the various lamp parts prior to and after being sealed together respectively; Fig. 6 is a perspective view of one half of the exhaust tube and leading-in wire holder of" the head; Fig. 7 is an end view of the head and fragmentary elevations of the heating burners and the seal compressing means associated with said head at station C and Fig. 8 is a perspective view of one of the burners, the compressing means and other portions of my apparatus associated with the lamp parts at station C.

The species of my invention shown in the drawing provides a plurality (twenty four) of heads I', only a few of which appear in Fig. 1, for supporting the lamp parts and for advancing said parts through a corresponding number of work stations in turn. The heads I are mounted along the outer edge of the turret 2 (only partially shown) and advance the lamp parts tothe work stations indicated on the dot-dash line 3 when influenced by the regular indexing movements of the turret 2, each revolution of the turret 2 representing one cycle of operation of the apparatus.

The initial steps in the cycle of operations of the apparatus wherein the lamp parts are fed either manually or mechanically into the apparatus occurs during the rest periods of the heads I in the course of the indexing movements thereof through th group A of work stations. The manner of operation is such that the exhaust tube 4 (Figs. 2 and i) is the first lamp part placed in the head I and said tube 4 is introduced end-foremost into an axial opening or passage in the holder 5 until it rests on the stop 6 (Figs. 2 and 6) At these stations, the jaws of the head I are in the open position (Fig. 3) and easy access is had to the holder 5 which comprises two similar halves 5 and 5" (FigsfS and '7) which are pivoted on pins I carried by the bracket 8 extending from the base 9 of the head I and which are pressed against each other by the contraction force of the springs It] and Ill. The springs ID and I0 extend between posts carried by the arms I I and II of respective halves. 5 and 5" of the holder 5 and corresponding posts of the adjacent heads I and function similarly in combination with the holders 5 of said heads I. The hollow stop plug 6 is held in place in the axial opening in the holder 5 by a stud 6 (Figs. 2, 6 and '7) which extends laterally therefrom through one half 5" of the holder 5 and is clamped in place by a nut. Next in the order of insertion is the cathode assembly I2 which consists of the cylindrical cup shaped cathode I3 with multiple section leadingin wires I4-I5 extending from the closed end thereof. The cathode assembly I2 is inserted in the head i in a manner which threads the ends of the leading-in wires I4 and i5 down through openings I6 and I1, respectively, in the holder 5 on opposite sides of the exhaust tube 4 and is completed when the ends of the relatively stiff wire I4 and I5 rest on the ends of the square stop rods 3 and I3, respectively, (Fig. 6) blocking the lower portion of said openings I6 and H. In this position the cathode assembly I2 is located in a substantially vertical position and the seal sections 20 of the leading-in wire l4-I5, which have substantially the same rate of expansion as the glass lamp parts, are located at a definite position in the head I. Should differentiength leading-in wires be used for some other desired arrangement of lamp parts such that an adjustment of position of the stop rods I8 and I9 is required, said adjustment can be mad-e after the nuts 2 I2I on the studs extending from the back of the clamping bar 22 are loosened. The stop rods I8 and I9 extend through openings 22' in the clamping bar 22 and are normally held at a fixed position by the binding effect of the sideward pull of the clamping bar 22 when the nut 2I and 2| are tightened. Should an adjustment of the position of the stop 6 be required, loosening the nut by which it is held will allow said stop 6 to be shifted vertically in a slot in the holder 5 to the required position.

Next in order of insertion is the vitreous en velope tube 23, which is to form th end portion of the envelope of the discharge lamp, and it is inserted into the head I at the last station of those indicated at A. At this last-mentioned station is located a flat stop plate 24 which functions as a limit means to establish the vertical position of the tube 23 which is passed over the end of the cathode assembly I2 and rested thereon as indicated in Fig. 4. The plate 24 is supported by a bracket 25 carried by a rod which extends from the stationary frame (not shown) of the machine and extends along the path of movement of the tube 23 taken during the subsequent indexing movement thereof.

The cycle of operations of the apparatus proresses with the index of the head I to station E as said movement first causes the jaws 26 and 21 to close and grip the vitreous envelope tube 23 and then causes the jaws 28 and 29 to close on and position the exhaust tube 4 and the leading-in wires I4 and I5. The heretofore described portions of the head I and the operating means therefore are similar to those disclosed in Patent 1,655,141 to J. T. Fagan et al., assigned to the assignee of the present invention. Both pairs of jaws 2521 and 2829 (Figs. 2, 3 and 7) are similarly mounted on corresponding levers 33 pivoted on the pins 3I, 3I' (only one of which appears in Fig. 2) in the base 9 of the head I and are actuated through means associated with the shaft 32 due to passage of the roller 33 on the arm 34 on the end of said shaft 32 from engagement with the cam 35 on the bracket 36 extending from the frame 31 of the apparatus underlying the turret 2 opposite stations A. While at these stations the jaws 26, 21

and 28, 29 are under the influence of a rotative movement of the shaft 32 which turns the double-throw cranks 38 or 39 so that the links 40, connecting said cranks 38 and 33 and the levers 33, hold the levers 30 and said jaws 26, 21

and 28, 29 in the open position. The passage of the head I beyond stations A, however, carries the head I beyond cam 35 thereby permitting the shaft 32 to become free of rotative influence excepting that produced by the contraction forces of the spring 4| and 42 which extend between the cranks 38 and 39 respectively and stationary posts (not shown) on the base of the next adjacent head I. The said posts correspond to posts 43 and 44 on the head shown in Fig. 2- which support the ends of springs 4| and 42' extending to cranks on the aforesaid next adjacent head. The double-throw cranks 38 and 39 are free to rotate about the shaft 32 and are influenced by said shaft 32 through the collars 45 and 46 respectively fastened thereto each of which engages, through a dog 41 (only one of Which is shown in Fig. 3) extending from its periphery, a pin 48 extending from either crank 38 or 39. In the present instance, the collars 45 and 46 are fastened to the shaft 32 at an angular relation so that the jaws 28 and 29 are opened wider by the rotative influence of the shaft 32 and, accordingly, close after jaws 26 and 2'! close.

Other operations in the cycle of the apparatus occur after the head I becomes located at station B, and comprise the application of heat to the lower end of the envelope tube 23 and the adjacent portion of the exhaust tube 4 by bringing the burners 49 and 58 (Figs. 1 and 2) into operative relation therewith. The means of moving the burners 49 and 58 corresponds to that disclosed in detail in the aforesaid Patent 1,655,141 and provides a common manifold 5I for supporting said burners 43 and 53 which manifold 5I is moved by means (not shown) controlled by the main driving means (not shown) of the apparatus so as to be timed with the indexing movements of the turret 2. The burners 49 and 50 are brought into operative relation to the head I and the juxtaposed ends of the envelope 23 and exhaust tube 4 during the rest period and are withdrawn from said relation to prevent interference with the head I during the index. The heat of the sealing operation is shielded from the operating means for the jaws 26, 27 and 28, 2-3 by the plate 52 which is attached to the base 9 of the head I and which is slotted so as to also function as a support for the levers 30 holding said jaws 26, 2? and 28, 29.

A further operation takes place at station B which consists in lowering the centering rod 53 to cause the end thereof to pass into the open upper end of the cathode I3 so that said cathode I3 is positioned centrally within the tube 23. The centering rod 53, which is slidable within the supporting bracket 54, is moved from an upper position, where the friction ball 55 en gages the circumferential groove 56 therein, by a downward movement of the arm 5'! (Figs. 1 and 2) which engages the top of the centering rod 53 through the adjustable push pin 58. During the preceding indexing movement of the head I, the friction of the ball 55, which is backed by the spring 59 in a well in the bracket 54, is sufficient to retain the centering rod 53 in the up position, the bracket 54 not being capable of adjustment vertically. The bracket 54 is mounted on the levers 30' which are, in turn, pivoted on the pin 3| and are supported at their outer ends in slots in the plate Bil. A support bracket BI mounted on the upstanding rods 62 and 63 extending from the base 9 of the head I: and engaging the pin 3| and plate 60 completes:the-retaining means for therod 53-.

The extentof the downward movement of the centering rod. 53 is determined by the movement of the arm 5'! which. is actuated through the rod 64 by the main driving means (not shown) of the. apparatus in: order to be moved in proper timed relation to the other operations thereof and isv moved. down until the friction ball 55 enters the second. circumferential groove 65 in rodis. In: this latter positiomthe pointed lower end of the centering rod 53' is completely within theiopcn end of the cathode l3, and the adjacent cylindrical. portion 53 is in engagement with the slightly inturned: lip at the upper end of the oathod'el3 so. that said cathode [3 can not deviate from the center of" the envelope tube 23; The arm 51 and rod. 64 are. raised to their upper position: before the succeeeding indexing move.- ment. takes. place, the centering rod 53 being retained. at the lowered position by the engagementof the friction ball 55 with the groove 65. Atsuch times the burners 49 and 5!] are also moved outward away from the turret 2 to prevent them: from. interfering withthe heads I The succeeding indexing movement of. the head I and other following movements thereof advance the lamp: parts from station B through stations 0, D and E inclusive where additional heat is applied to the lower end of the tube 23 and the adjacent; end ofthe exhaust tube 4. At each of these stations there are provided movable burners 49! and.50' (Figs. '7 and 8), corresponding to burners 49 and 50 at station B, which direct flames of considerable pressure against the tube-2:3 whereby it is gradually fused and pressed intoa solid mass about the exhaust tube 4. The passage through the exhaust tube 4 must be maintained during the above operations and, accordingly,,at.the series of stations C jets of air are directed up into the lower end thereof from the pipes 66 which terminate directly below the head I: at those stations. The air discharge by the pipe: 66 in each case enters the lower end. of the axial opening in the holder 5 containing the exhaust-tube 4 and passes up throughopenings in the clamping bar 22 and stop 6 to said. exhaust tube 4 where its pressure and cooling. effectprevents. collapse of the heated portion of the said tubing. 4.

Still other operations takev place at. station D. Thus, at this station. a tapered mandrel. 61 (Fig. 8-) is. raised through the openings in the holder 5, clamping bar 22, stop 6 and exhaust tube 4 until. it is located within the heated portion of the latter, and. the fused. portion of the tube 23 is further compressed by the jaws 58 and 69. The mandrel 61,. which is slidable longitudinally in the stationary guide tube 18' carried by the frame, of the apparatus, is moved up into position. by the main driving means (not shown) thereof just prior to the compressing of the tube 23! so. as to mold and. retain a passage through the compressed portion. The jaws 68 and 69-, on the other hand, which. are of corresponding. shape are pivotally mounted on pins 1 I --'l I extending from the. bracket 1.2 on the movable support post 13-, which post. 13 is the means of holding the manifold 5| for the burners 49' and 50 and is carried in a pivotal movement to andv from operative relation to. the heads I between indexing movements. thereof. The main driving means (not shown) of the apparatus provides the means of moving the support post 13 pivotally about the axis of shaft 14 through rotation of said shaft 1-4 to: WhiGhlthEzpQSll13; is fastened by tacks l5 and: also; actuates; the jaws 6.81 and 69. through vertical movement ofthe arm- 16 (only partially shown) to which each of the jaws is connected by a. corresponding: link. 11. The tube. 2:3 is engaged: by the: face: pieces 1-8 and 191 of. heat resisting. material on the jaws, 68 and 59, which face: pieces 1-8 and 19' are shaped so. as to. compress the tube 23 at the: center only. sufiiciently to: cause it to seal effectively to the end of the exhaust tube: 4- while compressing it at opposite sides of center'much more completely to causethe walls; of said; tube 232120. be brought into intimate contact with: the leading-in wires l4. and I5. In the; compressing. operation ears or lobes of solid vitreous material are formed onopposite sides of the tube 23 which ears or lobes completely surround the short intermediate seal portions. 20 of the leading-inwires 8'4 and I5 having the same particular rate of expansion as thevitreous material. To: assure a. stronger and more satisfactory seal, it is preferred that heated air be directed. down into the open upper end of the tubelfi by the pipe (Figs. 1 and 7) so that'that portion. of" the tube. 23' adjacent the" compressed portion isexpanded'and: rounded. out. The above operation: completesv those taking place at station D and. is followed by the index. of. the head I and lampparts: torthe next station in the series, following: separation of the laws 68 and 69 and the withdrawal of. the mandrel 61 The burners''a" and 50- at the four stations following station Dare adjusted to direct softer flames against the tube 23 so that it is little changed in shape. and annealed by the time the head: lis indexed from station E, the lastwork station: ofythe-i complete apparatus. Stations F through G, the. four directly followingstations taken. by the head- I,, are provided to allow the parts: to. cool: which: operation takes place in. the. course. of the. normal travel of the head throughthese stations; The lamp parts now are. completely joined together and appear as the assembl-yshownzinFig; 5.

Theremoval of the lamp assembly which takes place: at. station H; the last station taken by the head I: in. one. cycle ofoperation; can take place either manually or' mechanically, as desired, after the separation of the various; portions. of the apparatus from engagement therewith. In the present instance, the centering rod 5-3'is lifted at station: G from engagement with the cathode 13 by the corresponding mov ment of an. arm: 31 mounted on a vertical rod 82' (in the same manner as arm 51 and rod M at station B). The arm 8!: passes under the collar 83 on the centering rod'53: during: the indexing movement of the head I to station G and in its succeeding vertical movement engages the collar 83' and lifts the centering rod 53; The indexing movement of the head I to station H- carries the rollers and 84' on the arms I! and" H" extending from the halves 5" and 5"" respectively of the holder 5 against the stationary cam 86 (Figs. 1 and 2) causing said halves 5" and 5" to separate and the exhaust: tube 4 and leading-in wires [4* and. Hi to be free of the apparatus. The cam 86 is mounted on a bracket 8! extending from the frame 31 of the machine. The last step in the separation, of theapparatus from the lamp assembly is synchronized with the removal operation and: is brought about by the rotation of the arm 88 against the roller 33- on the arm 34- of the jawactuating means ofthe head I which operation causes the separation of the jaws 2 6- 21 and 28-29. The arm 88 is ivotally mounted on the bracket 81 and operated either manually or by the main driving means of the apparatus, as desired.

In other instances the presence of the centering rod 53 above the completed lamp assembly can block the desired manipulation of the lamp assembly during the removal thereof. In such instances, manual or mechanical sideward pressure on the bracket 54 will cause the centering rod 53, the bracket 54 and the levers 30' to swing to one side, giving ready access to the lamp assembly. The said sideward movement of the centering rod 53 may also be required to permit the insertion of the tube 23 by certain mechanical means at the start of the cycle of operation of the apparatus.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for sealing an end of a vitreous envelope tube and an end of a vitreous exhaust tube together about a leading-in wire extending from a cup-shaped cathode to form one end of a discharge lamp comprising; a head having means for supporting the envelope tube, means adjacent the first-mentioned means for holding the leading-in wire to retain a portion of said leading-in wire and the cathode held thereby within the envelope tube and for holding the exhaust tube with one end positioned within said envelope tube, and a centering means located on the opposite side of said first-mentioned means from the last-mentioned means and movable toward both said means through the open end of the envelope tube to engagement with the cathode for locating said cathode within the envelope tube; a movable carrier for supporting and advancing the head to a plurality of work stations; means at one station for moving the centering means toward said first-mentioned means and into proper engagement with the cathode; means at a succeeding station taken by the head for fusing the juxtaposed ends of the envelope and exhaust tubes together around a portion of the leading-in wires; and means at another succeeding station taken by the head for retracting the centering means to its position remote from the cathode to permit the ready removal of the envelope tube and cathode.

2. Apparatus for sealing an end of a vitreous envelope tube and an end of a vitreous exhaust tube together about a leading-in wire extending from a cup-shaped cathode to form one end of a discharge lamp comprising; a head having a pair of jaws for supporting the envelope tube, a holder adjacent the jaws with openings therein for retaining the leading-in wire and the exhaust tube so that a portion of said leading-in wire, the cathode held therby and one end of the exhaust tube are located within the envelope tube, and a centering rod located on the opposite side of the jaws from the holder and movable toward said holder through the open end of the envelope tube and into the open end of the cathode for locating said cathode within the envelope tube; a movable carrier for supporting and advancing the head to a plurality of work stations; means at one of said stations for moving the centering rod toward the holder and into proper engagement with the cathode; burners movable to and from the head at a succeeding station taken thereby for fusing the juxtaposed ends of the envelope and exhaust tubes together around a portion of the leading-in wires; and means at another succeeding station taken by the head for retracting the centering rod to its position remote from the cathode to permit the ready removal of the envelope tube and cathode.

3. In a mount making machine of the class described for assembling a glass tube and a tubular electrode having leading-in wires extending longitudinally therefrom, a head comprising support means including means for holding a glass tube and means for also supporting a tubular electrode by engagement with its leading-in wires at the exterior of the glass tube to support the said glass tube and electrode in approximate assembled relationship with the electrode within the glass tube and said leading-in wires extending through one end of said glass tube, a centering rod aligned with said support means to face the end of said glass tube opposite said one end thereof and having a tapered head adapted to enter the said electrode and center it in said glass tube, means mounting said centering rod for longitudinal movement first toward and through said glass tube into engagement with said electrode and then away therefrom, and means for fusing a portion of said one end of said glass tube about said leading-in wires during the time interval that said centering rod is in engagement with said electrode.

4. In a mount making machine of the class described for assembling a glass tube and a tubular electrode having leading-in wires extending longitudinally therefrom, a head comprising support means including means for holding a glass tube and means for also supporting a tubular electrode by engagement with its leading-in wires at the exterior of the glass tube to support the said glass tube and electrode in approximate assembled relationship with the electrode within the glass tube and said leading-in wires extending through one end of said glass tube, a centering rod aligned with said support means to face the end of said glass tube opposite said one end thereof and having a tapered head adapted to enter the said electrode and center it in said glass tube, means mounting said centering rod for longitudinal movement first toward and through said glass tube into engagement with said electrode and then away therefrom, said last-mentioned means further pivotally mounting said centering rod for lateral movement out of alignment with said support means, and means for fusing a portion of said one end of said glass tube about said leading-in wires during the time interval that said centering rod is in engagement with said electrode.

5. In a mount making machine of the class described, a head comprising jaws adapted to grip a glass tube, a holder below and aligned with said jaws having elongated bores adapted to receive and support the lower ends of lead wires having secured to their upper ends a tubular electrode with the said electrode located within said glass tube, said holder also having a central bore adapted to receive an exhaust tube with its upper end wthin said glass tube and means within said central bore defining an annular stop shoulder engageable by the lower end of said exhaust tube but leaving open the passage defined by said bore for insertion therethrough of a mandrel, a centering rod above and aligned with said jaws and having a tapered head adapted to enter the said electrode and center it in said glass tube, and means mounting said centering rod for longitudinal movement first toward and through said glass tube into engagement with said electrode and then away therefrom.

6. In a mount making machine of the class described, a-head comprising jaws adapted to grip a glass tube, a holder below and aligned with said jaws having elongated bores adapted to receive and support the lower ends of lead wires having secured to their upper ends a tubular electrode with the said electrode located within said glass tube, said holder also having a central bore adapted to receive an exhaust tube with its upper end within said glass tube and means within said central bore defining an annular stop shoulder engageable by the lower end of said exhaust tube but leaving open the passage defined by said bore for insertion therethrough of a mandrel, said holder being longitudinally divided in two through the several said bores, means mounting the two halves of said holder for movement apart to effect release of the exhaust tube and lead wires laterally therefrom, a centering rod above and aligned with said jaws and having a tapered head adapted to enter the said electrode and center it in said glass tube, and means mounting said centering rod for longitudinal movement first toward and through said glass tube into engagement with said electrode and then away therefrom.

7. In a mount making machine for assembling a glass tube and a tubular electrode having leading-in wires extending longitudinally therefrom, a head comprising support means including means for holding a glass tube and means for also supporting an electrode by engagement with its leading-in wires at the exterior of the glass 10 tube to support the said glass tube and electrode in approximate assembled relationship with the electrode within the glass tube, a centering rod, means on said head mounting said centering rod in alignment with said support means and for movement toward said support means through the end of said glass tube opposite said one end and into engagement with said electrode, a movable carrier supporting said head and adapted to advance the head to a plurality of work stations, means at one work station for moving the centering rod into engagement with said electrode, means at a succeeding station for fusing a portion of said one end of said glass tube about said leading-in wires, and means at another succeeding station for retracting the said centering rod away from the said electrode and glass tube.

JOHN FLAWS, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,872,070 McCabe et a1. Aug. 16, 1932 1,933,323 Pagan Oct. 31, 1933 1,942,042 Zimber et al Jan. 2, 1934 1,990,258 Trutner Feb. 5, 1935 2,104,166 Pelton Jan. 4, 1938 2,153,370 Donovan et a1. Apr. 4, 1939 2,411,184 Beggs Nov. 19, 1946 2,422,324 Watrous June 17, 1947 

